The present invention relates to a member mounting structure and a mounting apparatus for mounting a member such as a solid state image input unit, more specifically, relates to a member mounting structure and a member mounting apparatus for mounting a member such as a solid state image input unit utilized in copying machine, facsimile machine, image scanner and so on, in which an optical image is read by utilizing the solid state image input unit.
Generally, an image forming apparatus in which optical image is input as optical signal using a solid state image input unit such as CCD, inputs image of object 1 focused on solid state image input unit 3 through image forming lens unit 2 as shown in FIG. 46. In the solid state image input unit 3, one line of the solid state image input unit is utilized in which plurality of micro photoelectric converting devices (hereinafter it is referred to as merely xe2x80x9cpixelxe2x80x9d, which usually has a small dimension of some micrometers square) are arranged in a straight line.
In the image input unit as above described, in order to arrange a line image which is focused by the image forming lens unit 2, on the solid state image input unit and at the same time, in order to read out optical characteristics (focus, magnification and so on) in a predetermined accuracy level, it is required that the image forming lens unit 2 and the pixel line 4 of a line of solid state image input unit 3 are adjusted their position by micro movement along three axis directions such as X, Y and Z axes, and around two rotational directions such as xcex2 rotation around Y axis and xcex3 rotation around Z axis (hereafter rotational directions around the two axes referred merely to as movements along axes such as xcex2 axis and xcex3 axis, and X, Y, Z, xcex2 and xcex3 axes are merely referred to as five axes.) as shown in FIG. 47. At this time, the reference numeral 5 in FIGS. 46, 47 designates an axis of the lens unit 2.
At this point, the reason why an adjustment around X axis is not performed is that the distances between the image forming lens unit 2 and respective pixels of the solid state image input unit 3, become not different even when the adjustment along the X axis is not performed, because the X axis is located along (in parallel to) a direction of the line of pixels, in comparison with that the adjustments around the xcex2 and xcex3 axes cause the accuracy of optical characteristics to deteriorate because the distances between the image forming lens unit 2 and respective pixels of the solid state image input unit 3 become different when the adjustment around the xcex2 axis and xcex3 axis are not performed.
In the mean time, in order to input colored images there is a case in that the solid state image input unit 6 in which pixel R(6a), B(6b) and G(6c) having a peak of the spectroscopic sensitivity in Red (hereinafter referred to as merely xe2x80x9cRxe2x80x9d), Green (hereinafter referred to as merely xe2x80x9cGxe2x80x9d) and Blue (hereinafter referred to as merely xe2x80x9cBxe2x80x9d) respectively, are arranged in three lines respectively, is used as shown in FIG. 48.
Usually, accurate positioning adjustment of such solid state image input unit 6 is requested in high precision for every five dimension respectively, and what is seemed to be indispensable to attain the request is a technology by which positional discrepancy of positioning of solid state image input unit 6 is not happened when the solid state image input unit 6 is fixed onto a frame after the position of solid state image input unit 6 is adjusted as above stated.
The reason why such technology is requested is because even the positioning has been adjusted with high precision, when positional discrepancy happens at fixing, positioning adjustment must be performed again or separable members must be scraped in case of the fixing method in which parts are not separable.
To solve this kind of inconvenience it may take into consideration that complicated structural parts composed with arrowheads, balls and springs instead of screws are utilized, however, the cost increases much more because the complicated structural parts are expensive.
Accordingly, at present a fixing by adhesive material is mainly tried which is thought that amount of positional discrepancy is much less than that by screws and that problem regarding to number of members is much less. There are two methods in the fixing by adhesive material when it is classified roughly, one is a method for the case that objects to be fixed together are contacting each other, and another is a method for the case that objects to be fixed together are not contacting with a space.
At this time, the former is called as contacting adhering method and the latter is called as caulking adhering method.
In the caulking adhering method, there is a space which is larger than that for an adjusting, and the adhesive material is introduced and filled the space in order to fix the space. As a prior art technology of this kind in the caulking adhering method, there is a technique disclosed, for example, in Japanese Patent Laid Open Hei 7 (1995)-297993. The technology settles the space between the objects to be adhered so that the objects to be adhered would not contact each other even when they have problem of accuracy in shape and size and the adhesive material is filled between the space to fix.
Also, as a mounting method onto a head holding member through an ultraviolet curing adhesive material, there is a method as shown in FIG. 49.
In the method shown in FIG. 49, the adhesive material 12 is painted on one surface of a work piece 11 and the work piece 11 is adjusted for its positional relation to a work piece holding member 13 as shown in FIG. 49(A). When the work piece 11 is fixed onto the work piece holding member 13 through the adhesive material 12, by irradiating ultraviolet to the adhesive material 12 through a light guide L from a space between the work piece 11 and the work piece holding member 13, the adhesive material 12 is hardened to fix the work piece 11 onto the work piece holding member 13 as shown in FIG. 49(B). At this time, when either one of the work piece 11 or the work piece holding member 13 is made of a ultraviolet transparent material, the ultraviolet may be passed through the transparent material to irradiate the adhesive material 12.
However, in the prior art technique such as described above, because the amount of space is settled so that the objects to be fixed would not contact each other and the adhesive material is filled between the space to fix, problems as listed below have taken place.
Hereinafter, this caulking adhering method will be explained with reference to a drawing of one example as shown in FIG. 50, and the problems of it will be concretely explained.
In FIG. 50, the reference numeral 14 designates a work piece to be adhered, 15 designates a work piece holding member and 16 designates the adhesive material, the work piece 14 will be fixed onto the work piece holding member 15 by caulking the adhesive material 16 between the work piece 14 and the work piece holding member 15 and hardened in this example.
To adhere and fix the work piece 14 on the work piece holding member 15 without contacting each other, a space B is required in order to keep a space to be filled by the adhesive material 16 so that the adhered surface 14a of work piece 14 and the adhered surface 15a of work piece holding member 15 would not contact each other even when an amount of dispersion in positional discrepancy is A (space for positioning adjustment of the work piece 14) at the adhered surface 14a of work piece 14, and an amount of dispersion in positional discrepancy C at the adhered surface 15a of work piece holding member 15, occur.
In consequence of this, the film thickness of adhesive material 16 varies from B at the minimum and to A+B+C at the maximum, then it becomes dispersing in a range A+C.
Further, it may also become dispersing in a range I+J because of influence of a surface accuracy in the adhered surface 14a of work piece 14 and the adhered surface 15a of work piece holding member 15.
Generally, as the adhesive material shrinks when it is hardened, it becomes important that the film thickness of adhesive material must be reduced as little as possible in order for the objects to be fixed not to have the positional discrepancy after the adhesive material has been hardened. On the contrary, as the film thickness of adhesive material cannot be made less than B in the above described caulking adhering method, there was a case in that an improvement in the amount of positional discrepancy after fixing, could not be realized because changing of film thickness as a counter measure could not be applied even the positional discrepancy happened with amount much larger than the tolerable amount when the film thickness of adhesive material is B.
Because a dispersion of the film thickness happens within a range of A+C, the amount of shrinkage at the adhesive material after fixing, changes together in accordance with the dispersion. In consequence of this, the position of work piece 14 also disperses and there was a case in that the required accuracy could not be maintained. Commonly the volume shrinkage rate of ultraviolet curing adhesive material is in a range from 5 to 10 percent. Presuming a case that the volume shrinkage rate is 7%, it shrinks about 2% in each respective three directions when the hardening shape of adhesive material is cubic.
In consequence of this, when the difference in a level of about 0.5 mm occurs in the film thickness of adhesive material, it causes that about 10 xcexcm of differences in the shrinkage after hardened, occur in respective directions. In a case when the objects to be fixed are made by an injection molding of the resin, there can be a case in that above described dispersion of film thickness A+C becomes more than 0.5 mm, there is enough possibility that the positional discrepancy becomes a fatal problem.
As above described, because there may happen a case that the required accuracy of fixing position for an ink jet work piece is not maintained by the prior caulking adhering method, a yield in production line is made decreased or there must be a disposal for scrapping of the objects fixed, which is not good in accuracy of fixing, then they makes problem happened that costs for production are increased.
To solve this kind of problems, there is a technique disclosed in Japanese Laid Open Patent Hei 10(1998)-309801.
This member mounting structure is arranged in that lying an intermediate holding member between a work piece and a work piece holding member and then fixing the intermediate holding member onto the work piece by an adhesive material and at the same time, fixing the intermediate holding member onto the work piece holding member through the adhesive material. Because of this lying structure of the intermediate holding member between the work piece and the work piece holding member, by means of only controlling to make minimum for necessity and constant the film thickness of the adhesive materials those are used for a space between the adhered surfaces of the work piece and the intermediate holding member, and used for a space between the adhered surfaces of the work piece holding member and the intermediate holding member, this technology can achieve to attach the work piece onto the work piece holding member with high accuracy, and to keep high yield of production and at the same time, to prevent occurrence of decease in fixing force of the work piece after production without controlling the positional accuracy of adhering point of the work piece and the work holding member.
However, the above described technique has still problem to be improved when it is applied to a case that a solid state image input unit is the work piece and a solid state image input unit holding member is the work piece holding device and an intermediate holding member is lying through adhesive material between the solid state image input unit and the work piece holding member, because it has not a concrete structure in order to enable the high accuracy attachment of the solid state image input unit after the easy positioning adjustment in five axes of the solid state image input unit, in the positioning adjustment of the solid state image input unit before fixing by the adhesive material, a line image focused by an image forming lens unit is positioned on the solid state image input unit and an optical characteristics of them are measured with a required predetermined accuracy, and to prevent an occurrence of decrease in fixing force of the solid state image input unit after production.
In consequence of this, it is an object of the present invention to provide a mounting structure for mounting a solid state image input unit by which mounting of the solid state image input unit is enable to easily achieve a positioning adjustment in the five axes of the members of solid state image input unit with high accuracy after positioning adjustment has done in the five axes before fixing the solid state image input unit by adhesive material, and an image data input unit and an image forming apparatus which are made with the mounting structure.
In consequence of this, it is an object of the present invention to provide a mounting structure for mounting a solid state image input unit by which mounting of the solid state image input unit is enable to easily achieve a positioning adjustment in the five axes of the members of solid state image input unit with high accuracy after positioning adjustment has done in the five axes before fixing the solid state image input unit by adhesive material, and an image data input unit and an image forming apparatus which are made with the mounting structure.
To solve the above stated object, according to a first aspect of the present invention, a member mounting structure comprises: a first member; a second member on which a plurality of acting members are disposed along a line; and an intermediate holding member for holding the second member so as to oppose to the first member. The first member and the intermediate holding member are fixed by adhesive material; and at the same time, the second member and the intermediate holding member are fixed by adhesive material. The intermediate holding member is disposed so that a first adhered surface between the first member and the intermediate holding member, and a second adhered surface between the second member and the intermediate holding member are arranged parallely with the disposed direction of the plurality of acting members and at the same time, the first and second adhered surfaces are arranged to make a right angle.
In the structure when a positioning adjustment of the first member 101 and the second member 102 is performed, a positioning adjustment along X, Y and xcex3 axes can be achieved by means that intermediate holding member 103 is slid parallely with reference to the adhered surface of the first member 101, and a positioning adjustment along X, Z and xcex2 axes can be achieved by means that second member 102 is slid parallely with reference to the adhered surface of the intermediate holding member 103. As a result of this, the positioning adjustment with micro movement along only five direction of X, Y, Z, xcex2 and xcex3 axes except around X axis, can be easily achieved.
In other words, by means that the first adhered surface A between the first member 101 and the intermediate holding member 103, and the second adhered surface B between the second member 102 and the intermediate holding member 103 become parallel with the direction in which plurality of acting members of the second member 102 are disposed, and at the same time, the first adhered surface A and the second adhered surface B are arranged to make a right angle, the positioning adjustment in direction along only five axes of X, Y, Z, xcex2 and xcex3 can easily be adjusted so that the positioning adjustment along the X axis is not achieved in positive manner.
At this time, the reason why an adjustment of rotational axis around X axis is not performed is that the distances between the first member and the second member become not different without adjustment around X axis even when the adjustment around the X axis is not performed, because the X as is located along (in parallel to) a direction of the line of the acting members in comparison with that the adjustments around the xcex2 axis and xcex3 axis cause deteriorate the accuracy of optical characteristics because the distances between the first member and the second member become different when the adjustment of the xcex2 axis and xcex3 axis around the Y axis and Z axis are not performed.
After the positioning adjustment along five axes is completed the mounting of the second member is performed with high precision and yield of the process can get higher by means that thickness of the adhesive materials which are applied to the adhered surface between the second member and the intermediate holding member and the adhered surface between the first member and the intermediate holding member are controlled in the minimum requirement and constant value, and a positional accuracy of the adhered portions of second member and the first member do not have to be strictly controlled because the intermediate holding member is equipped between the second member and the first member, and at the same time, it can be prevented that an occurrence of deterioration in a fixing forth of the second member after the second member has been completed (after the adhesive material is hardened).
To solve the above stated object, according to a second aspect of the present invention, a mounting structure according to the first aspect wherein said second member comprising a disposing member on which said acting members are disposed, a substrate on which said disposing member is mounted, and a supporting member for attaching and detaching to support detachably said substrate, is provided is provided.
In such case, the second member can be ritualized again because the second member can be removed from the detachable supporting member when defective product in adhesion is made in mounting process at the first adhered surface or the second adhered surface or at both adhered surfaces.
To solve the above stated object, according to a third aspect of the present invention, a mounting structure according to first aspect of invention wherein said second member comprising a disposing member on which said acting members are disposed, and a supporting member for attaching and detaching to support detachably said substrate is provided.
In such case, the second member can be ritualized again because the second member can be removed from the detachable supporting member when defective product in adhesion is made in mounting process at the first adhered surface or the second adhered surface or at both adhered surfaces.
Also to achieve the above stated object, according to a fourth aspect of the present invention, a mounting structure according to the first aspect of the present invention wherein said structure further comprising a substrate on which said second member is mounted, and said substrate has a through hole to be penetrated by a part of said intermediate holding member when said second member is fixed on said intermediate holding member is provided.
In such case in positioning adjustment for the second adhered surface, the accurate positioning adjustment can be achieved when positioning adjustment of longer distance is required than a thickness of the second member and a width of space between the second member and the substrate on which the second member is mounted, because a longer adjustment space can be secured in Z direction by means that the second adhered surface is extending in direction of Z axis.
Further to achieve the above stated object, according to a fifth aspect of the present invention, a mounting structure according to the first aspect of the present invention wherein said structure further comprising a substrate on which said second member is mounted, and said second member is arranged so that said substrate does not abut on a part of said intermediate holding member when said second member is moved in a direction toward said first adhered surface to be fixed on said intermediate holding member is provided.
In such case in positioning adjustment for the second adhered surface, the accurate positioning adjustment can be achieved when positioning adjustment of longer distance is required than a width of the second member and a length of space between the second member and the substrate on which the second member is mounted, because a longer adjustment space can be secured in Z direction by means that the second adhered surface is extending in direction of Z axis.
Still further to achieve the above stated object, according to a sixth aspect of the present invention, a mounting structure according to claim 1 wherein said first member has a adjusting member to adjust a distance between opposing surfaces of said first member and said second member is provided.
In such case when the positioning adjustment cannot be completed by only a positioning adjustment of the second member, the accurate positioning adjustment can be achieved because the positioning adjustment for first member and second member can be achieved in Z direction.
Yet further to achieve the above stated object, according to a seventh aspect of the present invention, a mounting structure according to first aspect of the present invention wherein said first adhered surface crossed with an optical axis with right angle and a height of the optical axis is located between a width of said first adhered surface in vertical direction is provided.
In such a case a shrinkage at the intermediate holding member is transformed to a movement to come nearer (a slide) to the first member and the second member with regard to an effect of hardening age which occurs at a hardening of the adhesive material, the positional discrepancy at the second member itself can be suppressed and the first member can be located with high accuracy in relation to the second member.
Moreover, the whole structure can get a micro movement to adjust its position along the respective five directions of X, Y, Z, xcex2 and xcex3 axes by means that sliding adjustments are performed in the two surfaces being right angle each other (the first adhered surface A and the second adhered surface B).
Further again, the whole parts of structure can be contained in the minimum required space and occurrence of a restriction for the layout can be prevented because the first adhered surface and the second adhered surface can be included within the vertical range with the fundamental restricted area on the layout by means that the first adhered surface and the optical axis are located in the same height when viewing along the X direction.
According to a eighth aspect, the present invention is characterized by that plurality of said intermediate holding member are disposed and at least a pair of said intermediate holding member hold together said second member.
In such case, the structure can be much stronger to the external force and the mechanical vibration than a structure with the same number of intermediate holding member which are located all the same side.
Yet further to achieve the above stated object, according to a ninth aspect of the present invention, a mounting apparatus having members with a structure according to the first aspect of the present invention in which said first member is a holding member to hold a image forming lens unit, said second member is solid state image input unit which photoelectric converting image focused by said image forming lens unit, said apparatus comprising: a light source; an image for positioning adjustment illuminated by said light source for generating image to perform positioning adjustment of said solid state image input unit; and a fixing operation portion holding members having said structure according to claim 1 performing positioning adjustment of image forming lens unit and solid state image input unit and fixing them, wherein said image for positioning adjustment is focused on said solid state image input unit through image forming lens unit, and calculating relative position of image forming lens unit and solid state image input unit based on photoelectric converted focused data is provided.
In such case, the positioning adjustment can be accurately achieved even when the fluctuation of conjugate length happens at the image forming lens unit because a width can be set to adjust the width of error along Z axis.